1. Field of the Invention
The present invention relates to a decorative light string device, particularly to a decorative light string device having a voltage-doubling design.
2. Description of the Related Art
LED (Light Emitting Diode) emits light when electrons and holes recombine in a semiconductor material, wherein electrons drop to a lower energy level with light energy released. LEDs with different forbidden bands provide different colors of light. Currently, LEDs have been able to provide lights of a full color spectrum. Compared with the traditional lamp bulbs, LED has the advantages of luminescence, small size, fast response, drop proof, and high power efficiency. Therefore, LED has been extensively used in many products.
For example, LED has been widely used in decorative light strings. Refer to FIG. 1 for a conventional decorative light string device 10, which comprises: a power plug 12, a tail socket 14 coupled to the power plug 12, and a power converter 16 coupled to the power plug 12 and a LED string 18. The power converter 16 converts AC (Alternating Current) power into DC (Direct Current) power, and the DC power is supplied to the LED string 18.
When the original voltage is maintained, increasing the LED number of the LED string will decrease LED brightness. Only via raising voltage can the LED number of the LED string be increased without decreasing LED brightness. However, raising voltage increases power consumption and electric expense.
Accordingly, the present invention proposes a novel decorative light string device to solve the abovementioned problems.